Senior Network Engineer

About the job

Cognizant is seeking a Senior Network Engineer to design, implement, secure, operate, and optimize enterprise datacenter, campus, branch, wireless, and hybrid-cloud networks. This role requires advanced hands-on expertise in F5 BIG-IP, Palo Alto Networks, Cisco ACI, Cisco Nexus, Cisco Meraki, cloud networking, and enterprise DDI platforms. The engineer will serve as an L3 escalation point, lead major-incident troubleshooting, execute migrations and lifecycle upgrades, perform root cause analysis, and collaborate with security, cloud, application, server, and architecture teams.

Key Responsibilities

Network Engineering and L3 Operations

· Own complex P1/P2 incidents involving routing, switching, wireless, firewalls, load balancing, DNS, DHCP, IPAM, VPN, SD-WAN, and hybrid-cloud connectivity.

· Lead troubleshooting bridges, analyze packet captures and telemetry, restore service, document root cause, and implement permanent corrective actions.

· Prepare and execute implementation, validation, risk, dependency, and rollback plans for production changes and maintenance windows.

· Maintain network diagrams, standards, operating procedures, inventory, capacity plans, lifecycle roadmaps, and disaster-recovery documentation.

· Participate in on-call support, vulnerability remediation, compliance reviews, and vendor escalation activities.

F5 BIG-IP

· Configure and troubleshoot F5 BIG-IP LTM, including virtual servers, pools, nodes, monitors, profiles, SNAT, persistence, traffic policies, and SSL offload.

· Manage SSL/TLS certificates, ciphers, health checks, high availability, upgrades, backup, and recovery.

· Develop and troubleshoot iRules; experience with F5 DNS/GTM and Advanced WAF/ASM is preferred.

· Resolve latency, session persistence, SSL handshake, health-monitor, and traffic-distribution issues.

Palo Alto Networks

· Administer Palo Alto firewalls and Panorama, including zones, security policies, NAT, objects, App-ID, User-ID, URL filtering, threat profiles, and logging.

· Troubleshoot sessions, routing, policy matching, NAT, IPsec VPN, GlobalProtect, and application connectivity using logs, CLI tools, and packet captures.

· Perform PAN-OS upgrades, rulebase cleanup, recertification, migrations, and security-hardening activities.

Cisco ACI and Nexus

· Design and troubleshoot Cisco ACI fabrics using APIC, tenants, VRFs, bridge domains, application profiles, EPGs, contracts, filters, VMM integration, and L3Out.

· Configure Cisco Nexus 3K/5K/7K/9K platforms using VLANs, trunks, vPC, STP, HSRP, OSPF, BGP, VXLAN, and EVPN.

· Troubleshoot endpoint learning, contracts, routing adjacency, fabric health, interfaces, port channels, and Layer 2/Layer 3 connectivity.

· Support data-center migrations, segmentation, fabric expansion, software upgrades, and hardware refresh programs.

Cisco Meraki

· Design, deploy, and administer Cisco Meraki MX security appliances, MS switches, MR wireless access points, and the Meraki Dashboard.

· Configure Auto VPN, SD-WAN, traffic shaping, content and security policies, VLANs, DHCP, site-to-site VPN, client VPN, and high availability.

· Plan wireless networks using RF fundamentals, channel and power optimization, SSIDs, authentication, guest access, and roaming.

· Monitor organization and network health, analyze event logs and packet captures, manage templates and firmware, and troubleshoot branch, LAN, WAN, and Wi-Fi issues.

· Use Meraki APIs and automation workflows for inventory, configuration validation, monitoring, and large-scale deployment.

Cloud Networking

· Design and support Microsoft Azure and AWS connectivity across cloud and on-premises data centers.

· Azure: VNets, subnets, NSGs, UDRs, Load Balancer, Application Gateway, Azure Firewall, VPN Gateway, ExpressRoute, Private Link, and DNS.

· AWS: VPCs, subnets, route tables, Security Groups, NACLs, Transit Gateway, Elastic Load Balancing, Direct Connect, Route 53, PrivateLink, and Site-to-Site VPN.

· Troubleshoot asymmetric routing, overlapping address space, DNS, MTU, VPN, firewall, load-balancing, and cloud-to-data-center connectivity.

· Implement automation and Infrastructure as Code using Python, Ansible, Terraform, REST APIs, JSON, YAML, and Git.

DDI: DNS, DHCP and IPAM

· Administer enterprise DDI platforms, preferably Infoblox Grid, including DNS zones and records, DHCP scopes, reservations, failover, IPAM, and role-based access.

· Troubleshoot recursive and authoritative DNS, forwarding, delegation, DNSSEC, DHCP allocation, lease, and address-management issues.

· Maintain address plans, naming standards, DNS/DHCP resiliency, automation workflows, reports, upgrades, backups, and disaster-recovery procedures.

Required Qualifications

· Bachelor’s degree in computer science, Information Technology, Engineering, or equivalent practical experience.

· 8+ years of enterprise network engineering experience, including at least 3 years in a senior or L3 role.

· Advanced knowledge of TCP/IP, IPv4/IPv6, VLANs, STP, vPC, HSRP/VRRP, OSPF, BGP, VPN, QoS, NAT, wireless networking, and packet analysis.

· Hands-on production experience with F5 BIG-IP LTM, Palo Alto firewalls/Panorama, Cisco ACI/APIC, Cisco Nexus, and Cisco Meraki.

· Practical Azure and/or AWS networking experience, including private connectivity to on-premises environments.

· Hands-on DNS, DHCP, and IPAM experience with Infoblox or a comparable enterprise DDI solution.

· Experience with Wireshark, tcpdump, network monitoring, ITIL incident/problem/change processes, and technical documentation.

· Strong communication skills and the ability to coordinate high-severity incidents and complex changes.

This is a remote role. The salary range for this role is between $99,000 and $116,000 depending on the skills and qualifications of the candidate . Applications will be accepted till 11/11/2026.